diff --git a/fs/nls/nls_cp866.c b/fs/nls/nls_cp866.c
index c5f8222..bdc7cb3 100644
--- a/fs/nls/nls_cp866.c
+++ b/fs/nls/nls_cp866.c
@@ -13,7 +13,7 @@
 #include <linux/nls.h>
 #include <linux/errno.h>
 
-static wchar_t charset2uni[256] = {
+static const wchar_t charset2uni[256] = {
 	/* 0x00*/
 	0x0000, 0x0001, 0x0002, 0x0003,
 	0x0004, 0x0005, 0x0006, 0x0007,
@@ -96,7 +96,7 @@
 	0x2116, 0x00a4, 0x25a0, 0x00a0,
 };
 
-static unsigned char page00[256] = {
+static const unsigned char page00[256] = {
 	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 0x00-0x07 */
 	0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, /* 0x08-0x0f */
 	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, /* 0x10-0x17 */
@@ -123,7 +123,7 @@
 	0xf8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfa, /* 0xb0-0xb7 */
 };
 
-static unsigned char page04[256] = {
+static const unsigned char page04[256] = {
 	0x00, 0xf0, 0x00, 0x00, 0xf2, 0x00, 0x00, 0xf4, /* 0x00-0x07 */
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf6, 0x00, /* 0x08-0x0f */
 	0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, /* 0x10-0x17 */
@@ -138,20 +138,20 @@
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf7, 0x00, /* 0x58-0x5f */
 };
 
-static unsigned char page21[256] = {
+static const unsigned char page21[256] = {
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 0x00-0x07 */
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 0x08-0x0f */
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfc, 0x00, /* 0x10-0x17 */
 };
 
-static unsigned char page22[256] = {
+static const unsigned char page22[256] = {
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 0x00-0x07 */
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 0x08-0x0f */
 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 0x10-0x17 */
 	0x00, 0xf9, 0xfb, 0x00, 0x00, 0x00, 0x00, 0x00, /* 0x18-0x1f */
 };
 
-static unsigned char page25[256] = {
+static const unsigned char page25[256] = {
 	0xc4, 0x00, 0xb3, 0x00, 0x00, 0x00, 0x00, 0x00, /* 0x00-0x07 */
 	0x00, 0x00, 0x00, 0x00, 0xda, 0x00, 0x00, 0x00, /* 0x08-0x0f */
 	0xbf, 0x00, 0x00, 0x00, 0xc0, 0x00, 0x00, 0x00, /* 0x10-0x17 */
@@ -176,7 +176,7 @@
 	0xfe, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 0xa0-0xa7 */
 };
 
-static unsigned char *page_uni2charset[256] = {
+static const unsigned char *const page_uni2charset[256] = {
 	page00, NULL,   NULL,   NULL,   page04, NULL,   NULL,   NULL,   
 	NULL,   NULL,   NULL,   NULL,   NULL,   NULL,   NULL,   NULL,   
 	NULL,   NULL,   NULL,   NULL,   NULL,   NULL,   NULL,   NULL,   
@@ -184,7 +184,7 @@
 	NULL,   page21, page22, NULL,   NULL,   page25, NULL,   NULL,   
 };
 
-static unsigned char charset2lower[256] = {
+static const unsigned char charset2lower[256] = {
 	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 0x00-0x07 */
 	0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, /* 0x08-0x0f */
 	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, /* 0x10-0x17 */
@@ -220,7 +220,7 @@
 	0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, /* 0xf8-0xff */
 };
 
-static unsigned char charset2upper[256] = {
+static const unsigned char charset2upper[256] = {
 	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 0x00-0x07 */
 	0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, /* 0x08-0x0f */
 	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, /* 0x10-0x17 */
@@ -258,7 +258,7 @@
 
 static int uni2char(wchar_t uni, unsigned char *out, int boundlen)
 {
-	unsigned char *uni2charset;
+	const unsigned char *uni2charset;
 	unsigned char cl = uni & 0x00ff;
 	unsigned char ch = (uni & 0xff00) >> 8;